The present disclosure relates to a field-effect transistor, a method for operating a field-effect transistor, a corresponding control unit, and a corresponding computer program.
ChemFETs are field-effect transistors or transistors, the gate electrode of which is exposed to a gas in a carrier gas that is intended to be measured. They are capable of measuring minute concentrations of substances (for example, in the range between ppb and several ppm) in gasses.
ChemFETs can require a long time (for example, several minutes) in some cases until the response to an established gas concentration has stabilized, both in the case of an increasing concentration and in the case of a decreasing concentration. The decisive factor therefore is the kinetics of adsorption and desorption of the gas, which is supposed to be detected, at the electrode.
In applications, however, the concentration can change more quickly than it takes for the signal to stabilize. For example, it can be desirable to measure the concentration of a gas once every second and the concentration can also change within a few seconds, whereas the sensor would have to be exposed to a constant concentration for approximately one minute in order to obtain a stable, stationary signal.